Chapter 12 Nonrenewable Energy Resources Friedland Relyea Environmental

Chapter 12 Nonrenewable Energy Resources Friedland Relyea Environmental Science for AP ®, second edition © 2015 W. H. Freeman and Company/BFW AP® is a trademark registered and/or owned by the College Board ®, which was not involved in the production of, and does not endorse, this product.

Module 34 Patterns of Energy Use After reading this module, you should be able to • Describe the use of nonrenewable energy in the world and in the United States. • Explain why different forms of energy are best suited for certain purposes. • Understand the primary ways that electricity is generated in the United States.

Nonrenewable energy is used worldwide and in the United States • Fossil fuel A fuel derived from biological material that became fossilized millions of years ago. • Nonrenewable energy resource An energy source with a finite supply, primarily the fossil fuels and nuclear fuels. • Nuclear fuel Fuel derived from radioactive materials that give off energy.

Worldwide Patterns of Energy Use Worldwide annual energy consumption, by resource, in 2011. Oil, coal and peat, and natural gas are the major sources of energy for the world.

Worldwide Patterns of Energy Use Global variation in total annual energy consumption and per capita energy consumption. The 10 countries shown are among the largest and the smallest energy users in the world.

Worldwide Patterns of Energy Use • Commercial energy source An energy source that is bought and sold. • Subsistence energy source An energy source gathered by individuals for their own immediate needs. • Can include straw, sticks, and animal dung.

Worldwide Patterns of Energy Use Energy consumption in the United States from 1850 through 2012. Wood and then coal once dominated our energy supply. Today a mix of three fossil fuels accounts for most of our energy use. The recent increase in natural gas and decrease in oil and coal is quite evident.

Worldwide Patterns of Energy Use United States annual energy consumption by resource and end use in 2012. These graphs show energy consumption and end use in the United States. (a) United States annual energy consumption by fuel type in 2012. (b) United States end use energy sectors in 2012. Commercial includes businesses and schools.

Different energy forms are best suited for specific purposes • The best form of energy to use depends on the particular purpose for which it is needed. • It is possible to determine energy efficiency by calculating the energy return on energy investment (EROEI) EROEI = Energy obtained from fuel ÷ Energy invested to obtain fuel • The larger the value of EROEI, the more efficient the fuel.

Quantifying Energy Efficiency Inefficiencies in energy extraction and use. Coal provides an example of inefficiencies in energy extraction and use. Energy is lost at each stage of the process, from extraction, processing, and transport of the fuel to the disposal of waste products. • Dirty Power

Efficiency and Transportation • Nearly 30 percent of energy use in the United States is for transportation, This is an area in which efficiency is particularly important. • Transportation is achieved primarily through the use of vehicles fueled by petroleum products, such as gasoline and diesel.

Efficiency and Transportation

Efficiency and Transportation Overall fuel efficiency of U. S. automobiles from 1975 through 2013. As more buyers moved from cars to light trucks (a category that includes pickup trucks, minivans, and SUVs) for their personal vehicles, the fuel economy of the total U. S. fleet declined. Only recently has it begun to increase.

Electricity accounts for 40 percent of our energy use • Electricity can be generated from many different sources • Electricity is a secondary source of energy, meaning that we obtain it from the conversion of a primary source. • Energy carrier Something that can move and deliver energy in a convenient, usable form to end users.

The Process of Electricity Generation • All thermal power plants convert the potential energy of a fuel into electricity. • Turbine A device with blades that can be turned by water, wind, steam, or exhaust gas from combustion that turns a generator in an electricity-producing plant. • Electrical grid A network of interconnected transmission lines that joins power plants together and links them with end users of electricity.

The Process of Electricity Generation Steps for using coal to produce electricity: • The burning fuel from coal transfers energy to water, which becomes steam. • The kinetic energy contained within the steam is transferred to the blades of a turbine, a large device that resembles a fan. • As the energy in the steam turns the turbine, the shaft in the center of the turbine turns the generator. • This mechanical motion generates electricity.

The Process of Electricity Generation A coal-fired electricity generation plant. Energy from coal combustion converts water into steam, which turns a turbine. The turbine turns a generator, which produces electricity.

Efficiency of Electricity Generation • Combined cycle A power plant that uses both exhaust gases and steam turbines to generate electricity. • Capacity In reference to an electricitygenerating plant, the maximum electrical output. • Capacity factor The fraction of time a power plant operates in a year.

Efficiency of Electricity Generation • Cogeneration The use of a fuel to generate electricity and produce heat. Also known as combined heat and power. • For example, if steam is used for industrial purposes or to heat buildings it is diverted to turn a turbine first. • This improves the efficiency to as high as 90 percent.